1. Field of the Invention
The present invention relates to a stretcher which can be also used as a wheelchair. More particularly, the present invention relates to a frame coupling structure in a stretcher which can change its configuration to a wheelchair, a mechanism for supporting a head or a back of a patient, a lever device which is gripped when pushing by hand for movement, a support structure of a safety bar, and others.
2. Description of Related Art
There is a stretcher having a back portion which can be raised in accordance with a posture of a stretcher user such as a person in need of nursing case or a patient who finds it difficult to sit up or move by him/herself (they are generically referred to as a “patient” in this specification), or a stretcher which can be transformed into a wheelchair by raising a back portion and bending a leg portion downwards (Japanese patent application laid-open No. 52459-1998). Such a stretcher can be transformed into a wheelchair after transferring a patient who is in a recumbent position from a bed to the stretcher so that the patient can be moved in a sitting posture.
This type of stretcher, however, has various problems such as described below.
As a first problem, there is one concerning a frame coupling structure. That is, a frame of a conventional stretcher is assembled so as to be capable of being bent at parts corresponding to a lumbar or knees by coupling a plurality of pipes by pin and others so that they can swivel without restraint. For example, a right pipe on an upper body side and a right pipe on a lower body side are coupled with a left pipe on the upper body side and a left pipe on the lower body side respectively by different pins so as to be capable of swiveling without restraint. When the frame is constituted by separately coupling the right and left pipes with each other so as to be capable of swiveling in this manner, the torsion is generated in the frame, leading to the insufficient rigidity. Further, since a hole is directly formed to the pipe to insert a pin therethrough, the hole tends to be enlarged due to long-term use so that a bent portion may rattle, which is inferior in the durability.
Moreover, an armrest for preventing a patient from falling off and facilitating a comfortable posture for the patient is needed when the stretcher is transformed into a wheelchair. This requires a troublesome operation such as going to the trouble to attach after transformation into the wheelchair the armrest as an additional member which has been detached in the stretcher configuration or lifting up and fixing the armrest which has been kept down in the stretcher mode, thus resulting in the bad usability. In addition, when transferring a patient from the stretcher to a bed or from the bed to the stretcher, the strength which can withstand a weight of the patient is needed since the weight is also applied to the armrest portion. However, the conventional frame structure is a one-column support structure or a cantilever support structure, and hence stagger may be caused or the sufficient strength may not be obtained.
A second problem relates to stability of a patient during use in the wheelchair configuration. That is, since the patient may not be able to maintain the posture by him/herself, it is necessary to secure stability by firmly supporting the patient's body or head in order to prevent the off-balance or tumble of the patient when using the stretcher in the wheelchair configuration. However, in the conventional structure, since the inclination of a seat or a backrest is fixed when transformed into the wheelchair or no mechanism for supporting the body is provided, the patient may tumble down when he/she bends forward if a preferred position as a wheelchair is taken.
A third problem lies in that support of a head of a patient is not taken into consideration in particular in the conventional stretcher. For example, a patient is obliged to keep his/her head low in a flat stretcher consisting of one solid timber mat. This posture increases a blood flow to the head or brings a patient a sense of insecurity that he/she may slide off to the head portion side. Such a trouble may give a sense of discomfort or insecurity to a patient even if the time required for movement is short. Additionally, although a pillow is put on the stretcher in order to appropriately hold the head portion in some cases, the pillow may move to cause the head to slide off or the pillow may be lost, which is inconvenient. If the pillow is fixed to the mat, however, the pillow can be an obstacle for transferring a patient from the bed, which is not preferable. On the other hand, a stretcher having a head support portion provided thereto has been developed, but the head support portion is only partitioned from a portion supporting a part from neck down for the convenience sake, and a patient must take a uniform posture irrespective of his/her physical constitution or symptom. Such a problem is also common to the stretcher which can be transformed into a wheelchair as well as a general stretcher. When it is used as a stretcher, a mat forming a single plane must support the head of a patient. Further, when it is used as a wheelchair, it is hard for the patient to lean his/her head to take a comfortable posture.
A fourth problem relates to movement of a stretcher or transfer of a patent on the stretcher. That is, in a nursing-care system for transferring a patient from a bed to a stretcher or from the stretcher to the bed in a recumbent position, it is considered that, for example, a tool called a transfer bar is used to facilitate transfer of the patient (international patent publication No. WO99/30662).
When transferring a patient from a bed and the like to a stretcher by utilizing this transfer bar, a bracket must be set on the opposite side which is not in contact with the bed of the stretcher so that the transfer bar is rotatably supported. Here, since the bracket for supporting the transfer bar protrudes above the stretcher, it may be an obstacle for allowance or medical attention to a patient or may give annoyance when the bracket is attached. It is desired that the bracket can be detachable with respect to the stretcher.
If the bracket is detached each time, however, attachment and detachment take time, and a place for accommodating the removed bracket is also required. Further, the bracket removed from the stretcher may be lost in some cases. Additionally, when pushing and moving the stretcher, since the stretcher has such a structure as that a frame which is as tall as or lower than a mat surface must be grabbed, a nursing personnel or a caregiver must stoop to push and pull the stretcher, thereby resulting in a burden on the lumbar and the like.
A fifth problem concerns a safety bar provided in order to prevent a patient from falling off. That is, the safety bar must be detachable for transfer, but detaching the safety bar each time for transfer is troublesome and inconvenient. Moreover, storage of the removed safety bar is troublesome and it may be lost. Although a structure such that the safety bar is moved up and down to be retracted can be considered, no fluctuation is made at positions of the safety bar and its support structure in their widthwise directions in this case. Therefore, the safety bar protruding in the side direction from the mat becomes an obstacle to form a gap between the safety bar and the bed and the like when the stretcher is pulled alongside the bed and the like.